1. Field of the Invention
This invention relates to a nozzle plate, a method for manufacturing a nozzle plate, a droplet discharge head, and a droplet discharge apparatus.
2. Background Art
Printing apparatuses such as printers and film forming (printing) apparatuses used for manufacturing flat panel displays and semiconductor devices are based on coloring and film forming techniques where ink or film material is discharged and flown toward an object by inkjet technology.
The droplet discharge head used in the inkjet technology is typically called “inkjet head” and composed of precision components manufactured by making full use of sophisticated techniques. In particular, the nozzle plate having nozzle holes from which ink or film material is discharged greatly affects basic operating characteristics such as impact and flight characteristics, and hence requires extremely high machining accuracy.
JP-A 9-216368(Kokai) (1997) discloses a nozzle plate that can be formed with high machining accuracy using an SOI (silicon on insulator) wafer. This nozzle plate is based on an SOI wafer on which a support layer of silicon, a dielectric layer of silicon oxide, and an active layer of silicon are laminated in this order. The nozzle plate is manufactured by dry etching the active layer to form nozzle holes therethrough, and etching the support layer and the dielectric layer to form taper portions communicating with the nozzle holes.